1. Field of the Invention
The present invention relates to a circular spring band hose clamp for clamping a hose end onto a member such as a connecting pipe.
2. Prior Art Statement
The use of circular spring band hose clamps is well known in the art, wherein overlapping ends have outwardly extending members which are squeezed together to enlarge the band diameter for easy placement around the hose; then allowing the members to separate so that the band will tightly engage the outer surface of the hose. Such a clamp is disclosed, for example in U.S. Pat. No. 4,882,814 (Takahashi); U.S. Pat. No. 5,620,209 (Sauer); U.S. Pat. No. 5,675,871 (Webb et al.); and U.S. Pat. No. 5,996,186 (Yamada et al.).
An improved device is disclosed in U.S. Pat. No. 5,706,557, issued to Beicht, which further provides for one end of the band to engage the other end when the clamp expands under internal pressure and thus prevent further expansion of the band.
This invention also provides a hose clamp having a generally circular spring band with a clamping portion and opposite ends which overlap each other, the ends having outwardly extending tabs which may be held so that the clamp is radially unstressed and can be loosely place around the hose end. When the taps are released, the band tightly envelops the hose and contacts the outer surface; in the same manner as the prior art. However, as in the above-mentioned Beicht patent, the ends are adapted to inter-engage so that the clamp expands and holds this position even when internal stresses are applied to the hose, and further expansion of the band cannot occur. The novel clamp structure herein provides several features that perform the desired function in a superior manner. The outwardly extending tabs are spaced from each other at an angular distance of about 30 degrees when the band is in unstressed condition, this being accomplished by utilizing a stop member integral with the first tab, this stop member engaging the second tap. then when the squeezing force on the tabs is released, the band contracts radially until the stop member engages a selected one of the parallel series of locking members located on the clamping portion of the band which is adjacent to the second end. The selected locking member is one which provides the smallest possible diameter of the clamp in the radially stressed position. By locking the ends together, no further expansion of the band and clamp is permitted, despite increased internal forces on the hose.
It is a principal object of this invention, therefore, to provide a hose clamp comprising a spring band having two ends which interlock in a stressed position.
It is a further object to prevent said clamp from expanding under increased stress forces within the clamped hose.
It is another object to enable the clamp to reach an optimum locking position under stressed conditions.
These and other objects and advantages of the present invention will become apparent in the following specification and accompanying drawings.